Conventional Whole-breast Irradiation Research Articles

5126 Ipsilateral breast tumour relapse: local recurrence versus new primary and the effect of whole breast radiotherapy on the rate of new primaries

To examine the incidence and clinical relevance of fat necrosis after accelerated partial-breast irradiation (PBI) using interstitial high-dose-rate brachytherapy (HDR-BT) in comparison with partial-breast electron irradiation (ELE) and whole-breast irradiation (WBI).Between 1998 and 2004, 258 early-stage breast cancer patients were randomized to receive 50 Gy WBI (n = 130) or PBI (n = 128). The latter consisted of either 7 × 5.2 Gy HDR-BT (n = 88) or 50 Gy ELE (n = 40). The incidence of fat necrosis, its impact on cosmetic outcome, accompanying radiologic features, and clinical symptoms were evaluated.The 4-year actuarial rate of fat necrosis was 31.1% for all patients, and 31.9%, 36.5%, and 17.7% after WBI, HDR-BT and ELE, respectively (pWBI/HDR-BT = 0.26; pWBI/ELE = 0.11; pELE/HDR-BT = 0.025). The respective rate of asymptomatic fat necrosis was 20.2%, 25.3%, and 10% of patients. The incidence of symptomatic fat necrosis was not significantly different after WBI (8.5%), HDR-BT (11.4%), and ELE (7.5%). Symptomatic fat necrosis was significantly associated with a worse cosmetic outcome, whereas asymptomatic fat necrosis was not. Fat necrosis was detectable with mammography and/or ultrasound in each case. Additional imaging examinations were required in 21% of cases and aspiration cytology in 42%.Asymptomatic fat necrosis is a common adverse event of breast-conserving therapy, having no significant clinical relevance in the majority of the cases. The incidence of both symptomatic and asymptomatic fat necrosis is similar after conventional WBI and accelerated partial-breast HDR-BT.

Accelerated partial-breast irradiation vs conventional whole-breast radiotherapy in early breast cancer: A case-control study of disease control, cosmesis, and complications

Accelerated partial-breast irradiation (APBI) using various approaches is being increasingly employed for selected women with early breast cancer (EBC). To conduct a case-control study comparing disease control, cosmesis, and complications in patients with EBC undergoing APBI using multicatheter interstitial brachytherapy vs those receiving conventional whole breast radiotherapy (WBRT). Women with EBC fulfilling the American Brachytherapy Society (ABS) criteria were selected as 'cases' if treated with APBI or as 'controls' if offered WBRT during the period from May 2000 to December 2004. APBI patients were treated with high-dose-rate brachytherapy (HDR) to a dose of 34 Gy/10#/6-8 days. WBRT was delivered to the whole breast to a dose of 45 Gy/25# followed by tumor bed boost, either with electrons (15 Gy/6#) or interstitial brachytherapy (HDR 10 Gy/1#). At the median follow-up of 43.05 months in APBI and 51.08 months in WBRT there was no difference in overall survival (OS), disease-free survival (DFS), late arm edema, and symptomatic fat necrosis between the two groups. However, APBI resulted in increase in mild breast fibrosis at the tumor bed. Telangiectasias were observed in three patients of the APBI group. The cosmetic outcome was significantly better in the APBI group as compared to the WBRT group (P = 0.003). This study revealed equivalent locoregional and distant disease control in the two groups. APBI offered better overall cosmetic outcome, though at the cost of a slight increase in mild breast fibrosis and telangiectasias.

Breast cancer radiotherapy: controversies and prospectives

WBI takes 5–7 weeks, with attendant costs and inconveniences. This represents a significant hardship to certain subsets of patients and leads to disparity in breast cancer treatment. Obstacles such as inability to find an X-ray telescope (XRT) center close to home, difficulty in finding transportation to and from a center, lack of family support, and extreme age and/or physical handicap prevent some patients from electing to enter a 6-week course of WBI. Results from the breast-conserving therapy (BCT) trials suggest that up to 86% of the risk for ipsilateral breast cancer recurrence resides in close proximity to the original tumor site. This leads investigators to consider the role of an accelerated and more tumor bed-focused course of radiotherapy. APBI involves the treatment of a limited volume of breast tissue with a dose of irradiation per fraction increased and the treatment time course decreased. The goal is to deliver a dose of irradiation to a limited volume in less time, that is equivalent to the clinical outcome of the conventional 6-week treatment. 8 The importance of proper patient selection cannot be over-stressed when discussing the efficacy of APBI. This includes early stage breast cancer as determined by tumor size less than 2–3 cm, node-negative disease, age of patients more than 45–50 years, and tumor-free margins. 9,10 Additional criteria under study include features such as lobular histology, presence of extensive intraductal component (EIC), lymphvascular invasion, tumor grade and limited node-positive disease. When the tumor histology demonstrates a higher risk for multicentric disease and thus a higher rate for non-tumor bed cancer recurrence, the patients should not be

Clinical Experience Using Hypofractionated Radiation Schedules in Breast Cancer

Hypofractionation is attractive for whole- or partial-breast irradiation because it permits treatment to be given with fewer fractions in a shorter period of time and at less cost. A number of cohort studies suggest that hypofractionation may be given to the whole breast safely and with good local control. Recent randomized trials have confirmed that hypofractioned whole-breast irradiation is equivalent to more conventional whole-breast irradiation with respect to local recurrence and cosmetic outcome. Recently, there has been a renewed interest in hypofractionation for the delivery of partial-breast irradiation using a number of techniques including high-dose rate brachytherapy, 3-dimensional conformal radiation using external-beam techniques, and intraoperative therapy. Early cohort studies report good local control and acceptable morbidity. Randomized trials are now underway to compare this approach to conventional whole-breast irradiation.

Accelerated Whole Breast Irradiation With Intensity-Modulated Radiotherapy to the Prone Breast

Whole breast irradiation (WBI) is the standard of care for patients with early-stage breast cancer who opt for breast conservation. After a randomized trial demonstrated equivalent cosmesis and disease control with accelerated WBI (AWBI), our institution began to offer AWBI to appropriate patients. The aim of this study was to examine our unique experience with AWBI using prone positioning and simplified intensity-modulated radiotherapy (IMRT) planning with a sequential boost to the tumor bed. We identified 356 patients who had been treated with prone WBI using IMRT in our department between January 2004 and December 2006. Of these, 128 (36%) patients had received AWBI (representing 131 treated breasts), consisting of 16 daily fractions of 265 cGy to a total dose of 4,240 cGy followed by a conventionally fractionated boost. Patients who opted for AWBI were similar demographically to the patients undergoing conventional WBI. In the AWBI cohort, 83% of the patients had Stage T1 disease and 22% had nodal involvement (N1). The tumors were estrogen receptor-positive, progesterone receptor-positive and Her-2/Neu-amplified in 82%, 69%, and 11%, respectively. The median duration of AWBI plus a boost was 29 days, and no patient required a toxicity-related treatment break. No Grade 3 or greater acute toxicity developed. At a median follow-up of 18 months, one ipsilateral breast recurrence developed that was salvaged with mastectomy and immediate reconstruction. AWBI to the prone breast using simplified IMRT with a sequential boost offers women requiring breast-only adjuvant radiotherapy an abbreviated treatment with early tumor control and cosmesis comparable to that with standard fractionation.

Breast-Conserving Treatment With Partial or Whole Breast Irradiation for Low-Risk Invasive Breast Carcinoma—5-Year Results of a Randomized Trial

To report the 5-year results of a randomized study comparing the survival and cosmetic results of breast-conserving treatment with partial breast irradiation (PBI) or conventional whole breast irradiation (WBI). Between 1998 and 2004, 258 selected patients with T1 N0-1mi, Grade 1-2, nonlobular breast cancer without presence of extensive intraductal component and resected with negative margins were randomized after breast-conserving surgery to receive 50 Gy/25 fractions WBI (n = 130) or PBI (n = 128). The latter consisted of either 7 x 5.2 Gy high-dose-rate (HDR) multicatheter brachytherapy (BT; n = 88) or 50 Gy/25 fractions electron beam (EB) irradiation (n = 40). At a median follow-up of 66 months, the 5-year actuarial rate of local recurrence was 4.7% and 3.4% in the PBI and WBI arms, respectively (p = 0.50). There was no significant difference in the 5-year probability of overall survival (94.6% vs. 91.8%), cancer-specific survival (98.3% vs. 96.0%), and disease-free survival (88.3% vs. 90.3%). The rate of excellent to good cosmetic result was 77.6% in the PBI group (81.2% after HDR BT; 70.0% after EB) and 62.9% in the control group (52.2% after telecobalt; 65.6% after 6-9-MV photons; p(WBI/PBI) = 0.009). Partial breast irradiation using interstitial HDR implants or EB to deliver radiation to the tumor bed alone for a selected group of early-stage breast cancer patients produces 5-year results similar to those achieved with conventional WBI. Significantly better cosmetic outcome can be achieved with carefully designed HDR multicatheter implants compared with the outcome after WBI.

Fat Necrosis After Partial-Breast Irradiation With Brachytherapy or Electron Irradiation Versus Standard Whole-Breast Radiotherapy—4-Year Results of a Randomized Trial

To examine the incidence and clinical relevance of fat necrosis after accelerated partial-breast irradiation (PBI) using interstitial high-dose-rate brachytherapy (HDR-BT) in comparison with partial-breast electron irradiation (ELE) and whole-breast irradiation (WBI). Between 1998 and 2004, 258 early-stage breast cancer patients were randomized to receive 50 Gy WBI (n = 130) or PBI (n = 128). The latter consisted of either 7 x 5.2 Gy HDR-BT (n = 88) or 50 Gy ELE (n = 40). The incidence of fat necrosis, its impact on cosmetic outcome, accompanying radiologic features, and clinical symptoms were evaluated. The 4-year actuarial rate of fat necrosis was 31.1% for all patients, and 31.9%, 36.5%, and 17.7% after WBI, HDR-BT and ELE, respectively (p(WBI/HDR-BT) = 0.26; p(WBI/ELE) = 0.11; p(ELE/HDR-BT) = 0.025). The respective rate of asymptomatic fat necrosis was 20.2%, 25.3%, and 10% of patients. The incidence of symptomatic fat necrosis was not significantly different after WBI (8.5%), HDR-BT (11.4%), and ELE (7.5%). Symptomatic fat necrosis was significantly associated with a worse cosmetic outcome, whereas asymptomatic fat necrosis was not. Fat necrosis was detectable with mammography and/or ultrasound in each case. Additional imaging examinations were required in 21% of cases and aspiration cytology in 42%. Asymptomatic fat necrosis is a common adverse event of breast-conserving therapy, having no significant clinical relevance in the majority of the cases. The incidence of both symptomatic and asymptomatic fat necrosis is similar after conventional WBI and accelerated partial-breast HDR-BT.

Is partial breast irradiation a step forward or backward?

Partial-breast irradiation (PBI) may prove to be a significant advance in the treatment of selected patients with early-stage breast cancer. However, because PBI treats a much smaller volume of breast tissue than does conventional whole-breast irradiation and the biologic equivalent dose delivered to the tumor may be considerably lower, it is possible that this treatment approach may increase the risk of recurrence. There may also be an increased risk of toxicity using PBI techniques that have significant dose inhomogeneity. Despite these uncertainties, many patients in the United States are currently treated with PBI outside of a clinical study. Showing that PBI is safe and effective requires having results from large clinical trials. If such trials are supported and completed, the benefits and limitations of PBI are likely to be elucidated, and this treatment technique, properly refined, may well prove to be an advance in breast cancer care. If instead PBI is adopted ad hoc within the radiation oncology community without proper testing, it is likely that poor outcomes will be underreported and many patients will receive suboptimal therapy. This would be a big step backward in the role of radiation therapy in breast cancer treatment.